The major stock averages closed mixed Wednesday for a second straight day in mixed volume. The only uniform action? Tight rangebound trade across the market. The Nasdaq composite stopped a two-day selling streak with a 0.2% rebound. Volume fell. The day's range of 3106 to 3124 represented a narrow intraday spread of less than 0.6%. It had lost less than 0.3% in the prior two down days. The S&P 500 inched ahead less than one point. It too traded in